But why should others be inconvenienced by your decision to buy your
ticket on the bus when it would not cause you any inconvenience if they
were to get on while you were paying?

Because I have stood in a queue and am entitled to maintain that same position
as I enter the bus. If, as is often the case, only limited seating is
available, I, and not someone behind me, is entitled to choose which seat I
have before the person queue-jumping.

To say that I have "inconvenienced" someone by not having prepaid my ticket is
simply ludicrous.

Marc.